In general, in order to connect pipes, a method of welding pipes or fastening pipes after forming screw threads at end portions of the pipes has been used in accordance with materials of the pipe. However, there is a problem in that large costs and labor are required in this pipe connection technology.
As a technology presented to solve the aforementioned problem, a technology has been known in which one pipe and the other pipe are made face to each other, a connector socket is provided at an outer diameter of the facing pipes, and an O-ring is provided between the connector socket and the pipe.
Here, a condition that the pipe and the connector socket are not separated from each other needs to be satisfied, and an abnormal distortion of the O-ring needs to be prevented in order to maintain an airtight state.
However, according to a known technology, a stopper grip ring is used to prevent the pipe and the connector socket from being separated from each other. The stopper grip ring does not have a complete circular shape but have a C shape of which one side is opened. Therefore, in a case in which the stopper grip ring is provided at one side of the O-ring, there is a problem in that an end portion of the stopper grip ring causes damage to a part of the O-ring when the stopper grip ring is made narrower or broader.
Meanwhile, as a known technology presented to solve the aforementioned problem concerning damage to the O-ring, there is a technology in which a separating ring is further disposed between the stopper grip ring and the O-ring. However, because the number of components is increased in a case in which the separating ring is further provided, there is a problem in that costs for connecting pipes are increased.
Alternatively, as a technology that substitutes for the function of the separating ring, a technology has been known in which a part of the connector socket protrudes in an inner diameter direction when the connector socket is formed, the O-ring is disposed at one side of the protruding portion, and the stopper grip ring is disposed at the other side of the protruding portion. However, in a case in which a seat for receiving the O-ring is independently formed at a part of an end portion of the connector socket, there is a problem in that forming is difficult due to a complicated shape, special jigs and tools also need to be provided to process the special shape, and dimensional accuracy of the shape deteriorates because the specific shape is formed by repeatedly bending metal.